JPWO2010087361A1 - RTM molding method and method for producing fiber-reinforced resin molding - Google Patents

Abstract

A temperature control mechanism for adjusting the temperature of the mold provided in at least one of the plurality of molds forming the mold, and supply of resin in a state of having fluidity to the cavity of the mold And a plurality of the valve mechanisms are provided in the mold, and each of the plurality of valve mechanisms adjusts the temperature of the valve mechanism. The temperature control system is provided, and the resin having the fluidity is supplied from the plurality of valve mechanisms to the cavity, and is supplied to the reinforcing fiber base accommodated in the cavity. RTM molding method to be impregnated.

Description

  The present invention relates to an RTM (Resin Transfer Molding) molding method for a fiber reinforced resin (FRP) molded article, and in particular, to obtain a molded article having excellent surface quality while efficiently performing a process of injecting a resin into a mold. The present invention relates to an RTM molding method that can be used. Moreover, this invention relates to the manufacturing method of the fiber reinforced resin molded object which manufactures a fiber reinforced resin molded object using this RTM molding method.

  FRP, especially carbon fiber reinforced resin (CFRP), is being used in various fields as a composite material that is lightweight and has high mechanical properties. As a method for molding FRP, a prepreg, which is an intermediate material in which a reinforcing fiber base material is impregnated with a resin in advance, is placed on a mold, and the resin impregnating the reinforcing fiber base material in an autoclave is used. A method of solidifying is known. In many cases, a plurality of prepregs are stacked and placed on a mold.

  However, in recent years, a reinforcing fiber base material made of reinforcing fiber fabric or the like is placed on the mold, and after the mold is closed, the inside of the mold is decompressed to have fluidity. An RTM molding in which a thermosetting resin or a thermoplastic resin in a fluid state is injected into a cavity of a mold, the resin is impregnated into a reinforcing fiber base, and the resin is solidified Since the method can obtain a high-quality molded product in a short molding cycle, it has been widely used (Patent Document 1). When the resin is a thermosetting resin, the term “curing” may be used instead of the term “solidification”.

  Such an RTM molding method has a problem in that the resin forming the molded product remains and solidifies at the resin injection port into the cavity of the molding die and its vicinity, so that it takes a long time to remove the resin. It was. In order to solve this problem, a resin tube is used to inject a resin into a cavity at a mating surface of a plurality of molds in a molding die, and a plurality of resin tubes are closed when the plurality of molds are closed after the resin is injected. A method of clamping with a mold has been proposed. After the molded product was molded, the molded product was taken out from the mold, and the resin tube in which the resin remaining inside was solidified was taken out and discarded. A new resin tube is used for the next molding. This technique has been proposed as a technique for shortening the molding cycle time by reducing the cleaning work of the mold (Patent Document 2).

  However, even with this method, the resin tube sandwiched between the plurality of molds is solidified by the heat received from the mold, and cannot be used for the next resin injection. Therefore, there is a problem that a resin tube replacement operation or a used resin tube disposal operation is required for each molding cycle. Moreover, the resin tube which inject | pours resin to a cavity can be arrange | positioned only on the mating surface of the some type | mold of a shaping | molding die. Therefore, when molding a molded product having a shape in which the flow distance of the resin becomes long, for example, a molded product having a large surface area, there is a problem that it is difficult to shorten the impregnation time of the resin to the reinforcing fiber base. .

JP 2007-007910 A JP 2005-169786 A

  In view of the above problems in the prior art, the object of the present invention is to enable the injection of resin into the mold (that is, the cavity) without using a disposable resin tube in the RTM molding method. RTM that can obtain a fiber-reinforced resin molded article excellent in surface quality that enables the next resin injection without replacing the resin tube or disposing of the used resin tube at the start of the process. To provide a molding method.

  Further, by providing a resin injection port in at least one of the plurality of molds at a position other than the mating surfaces of the plurality of molds, even in the molding of a molded product having a large surface area, An object of the present invention is to provide an RTM molding method capable of shortening the impregnation time of the resin into the contained reinforcing fiber base.

  Moreover, the subject of this invention exists in provision of the manufacturing method of the fiber reinforced resin molded object which manufactures a fiber reinforced resin molded object using the RTM molding method which concerns on this invention.

  The RTM molding method according to the present invention is as follows.

(A) a plurality of molds, (b) a temperature control mechanism for adjusting the temperature of a mold provided in at least one of the plurality of molds, and (c) a mold opening / closing mechanism for opening and closing the plurality of molds, (D) When the plurality of molds are closed, a cavity formed between the inner wall surfaces of the plurality of molds, and (e) supplying resin in a fluid state to the cavities. A molding die comprising a resin introduction path and (f) a valve mechanism that is provided in the resin introduction path and starts and stops the supply of the resin from the resin introduction path to the cavity; (g) After the reinforcing fiber base is accommodated in the cavity, the plurality of molds are closed by the mold opening / closing mechanism, and (h) after the plurality of molds are closed, the resin is removed from the resin introduction path. Supplied to the cavity via the valve mechanism, (i) After the supply of fat is completed, the supply of the resin is stopped by the valve mechanism, and (j) the resin impregnated in the reinforcing fiber base in the cavity is solidified by the temperature control mechanism. The temperature in the cavity is adjusted, and (k) after the resin is solidified, the mold opening / closing mechanism opens the plurality of molds, and the fibers are made of the reinforcing fiber base and the resin. In the RTM molding method in which the reinforced resin molding is taken out of the mold,
(L) A plurality of the valve mechanisms are provided in the mold,
(M) Each of the plurality of valve mechanisms is provided with one or more temperature control systems for adjusting the temperature of the valve mechanism,
(N) The RTM molding method in which the resin having the fluidity is supplied from the plurality of valve mechanisms into the cavity.

  In the RTM molding method of the present invention, the fluidity is controlled in the cavity by continuously flowing a temperature adjusting medium in at least one of the one or more temperature control systems provided in the valve mechanism. Even when the resin in a state of having a solidification is performed, the flowability of the resin staying in the resin introduction path in the state where the flow of the resin in the resin introduction path is stopped is reduced. It is preferable that the resin in the state which it has is hold | maintained in the state which has fluidity | liquidity.

  In the RTM molding method of the present invention, the valve mechanism is embedded in the mold at a tip portion that is a part thereof, and the tip of the resin introduction path forms the cavity through the valve mechanism. In a state where at least one of the one or more temperature control systems provided in the mold so as to open to the inner wall surface and provided in the valve mechanism is stopped in the resin flow in the resin introduction path. It is preferable that the system is located between the resin retaining portion where the resin having the fluidity in the resin introduction path stays and the tip portion of the valve mechanism.

  In the RTM molding method of the present invention, the system located between the resin retaining portion and the tip end portion of the valve mechanism is provided with a temperature adjustment medium in a temperature adjustment medium flow path provided inside the valve mechanism. Preferably, the valve mechanism is cooled by the temperature adjusting medium.

  In the RTM molding method of the present invention, it is preferable that another temperature control system is disposed at the tip of the valve mechanism, and the other temperature control system heats the valve mechanism.

  In the RTM molding method of the present invention, it is preferable that a diameter d and a depth h of the tip portion of the valve mechanism satisfy a relationship of d ≦ h.

  In the RTM molding method of the present invention, it is preferable that the plurality of valve mechanisms are independently opened and closed.

  In the RTM molding method of the present invention, it is preferable that the temperature control mechanism provided in the mold includes a temperature control mechanism of a different system in the peripheral portion of the tip portion of the valve mechanism and other portions.

  In the RTM molding method of the present invention, among the temperature control mechanisms provided in the mold, the mold is such that the temperature control mechanism around the tip of the valve mechanism surrounds the tip of the valve mechanism. It is preferable that it is arrange | positioned.

  In the RTM molding method of the present invention, the temperature control mechanism provided in the molding die is arranged at a position where the distance L from the interface between the tip portion of the valve mechanism and the die satisfies the relationship of L ≦ 30 mm. It is preferable to be provided.

  In the RTM molding method of the present invention, a plurality of the resin introduction paths including the plurality of valve mechanisms are coupled to the same resin supply source, and the plurality of resin introduction paths connecting the resin supply source and the valve mechanism to the resin introduction paths, A supply resin temperature adjusting mechanism for adjusting the temperature of the resin is provided at a temperature higher than the temperature of the resin when introduced into the cavity, and the temperature of the resin in the resin introduction path is adjusted by the supply resin temperature adjusting mechanism. It is preferable to adjust.

  In the RTM molding method of the present invention, the reinforcing fiber substrate is preferably in the form of a sheet.

  In the RTM molding method of the present invention, it is preferable that the reinforcing fiber base material has a core material therein.

  In the RTM molding method of the present invention, in the cavity, there is a resin flow path forming medium in the cavity between the opening position on the inner wall surface of the mold of the resin introduction path and the reinforcing fiber substrate. It is preferable that they are arranged.

  In the RTM molding method of the present invention, it is preferable that the thickness of the media is 0.2 to 1 mm.

  The manufacturing method of the fiber reinforced resin molding which concerns on this invention is as follows.

  The manufacturing method of the fiber reinforced resin molded object which manufactures a fiber reinforced resin molded object using the RTM molding method of this invention.

  According to the RTM molding method of the present invention, when a liquid resin (resin in a state having fluidity) is injected into a molding die and the resin is solidified in the molding die, Inadequate solidification of the liquid resin can be prevented, and desired smooth resin injection operation and smooth start and stop operations of resin injection can be performed. Moreover, since the injection resin can be prevented from solidifying, the resin flow path can be opened and closed without using a disposable resin tube. Therefore, the workability of the entire molding cycle can be improved, and the productivity of the molded product can be improved. In addition, it is possible to reduce wastes such as resin tubes that have been generated conventionally.

  Further, if such an RTM molding method is used, the resin can be smoothly injected into the cavity of the molding die, and the tact time can be shortened when repeatedly molding, so that the FRP molded product can be reduced. Production efficiency can be greatly increased.

  Regarding the term of resin solidification, when the resin is a thermosetting resin, the term of curing is usually used, and when the resin is a thermoplastic resin, the term of solidification or solidification is usually used.

FIG. 1 is a schematic partial cross-sectional front view of an example of a mold for carrying out the RTM molding method of the present invention. FIG. 2 is a schematic partial cross-sectional enlarged front view showing a state in which resin flows in a resin introduction path of the valve mechanism in the molding die shown in FIG. 1 (communication state of the introduction path). 3 is a schematic partial cross-sectional enlarged front view showing a state in which resin does not flow in the resin introduction path of the valve mechanism shown in FIG. 2 (closed state of the introduction path). FIG. 4 is a schematic partial cross-sectional front view showing a state where the resin does not flow in the resin introduction path as an example of another embodiment of the valve mechanism in the mold shown in FIG. 1 (closed state of the introduction path). FIG. 5 is a schematic partial cross-sectional front view of the valve mechanism in which a preferable dimensional relationship is additionally displayed on the valve mechanism shown in FIG. FIG. 6 is a schematic plan view taken along the 2S-2S section of the periphery of the tip of the valve mechanism shown in FIG. 2, and shows an example of the positional relationship between the temperature control mechanism and the tip of the valve mechanism. FIG. 7 is a schematic plan view of another aspect of the temperature control mechanism shown in FIG. FIG. 8 is a schematic plan view of still another aspect of the temperature control mechanism shown in FIG. FIG. 9 is a schematic partial cross-sectional front view of another embodiment of the mold shown in FIG. 1.

  One embodiment of a mold used for carrying out the RTM molding method of the present invention is shown in FIG. In FIG. 1, the mold 1A has a plurality of molds, for example, an upper mold 1 and a lower mold 2. A temperature control mechanism 5 a for adjusting the temperature of the mold is provided in at least one of the plurality of molds 1, 2, for example, the upper mold 1. In this embodiment, the temperature control mechanism 5b is also provided inside the lower mold 2. These temperature control mechanisms 5a and 5b are formed by, for example, a medium flow path through which a temperature adjusting medium embedded in the upper mold 1 flows, or an electric heating element (for example, an electric heater) capable of controlling temperature.

  The temperature control mechanisms 5a and 5b shown in FIG. 1 include a medium flow path through which a temperature adjusting medium flows. In the medium flow path, a circulating medium supplied from a medium supply device provided outside the mold 1A is circulated. The medium is heated or cooled depending on the purpose. For example, water or oil is used as the medium.

  The mold 1A includes a mold opening / closing mechanism 1B that opens and closes the plurality of molds 1 and 2. The mold opening / closing mechanism 1 </ b> B is attached to the elevating lower board 23 attached to the lower mold 2, the support 22 attached to the upper mold 1, the elevating upper board 21 attached to the upper part of the support 22, and the elevating upper board 21. And an elevating mechanism 1Bd for elevating the elevating upper board 21. In this embodiment, the lifting / lowering board 23 is fixed to the base (not shown) of the mold 1A and does not move in the vertical direction. Therefore, the position of the lower mold 2 is also fixed. The upper mold 1 is separated from the lower mold 2 by the lifting mechanism 1Bd. As a result, both the molds are opened and closed between the upper mold 1 and the lower mold 2. An O-ring 17 for sealing is provided on the upper surface of the lower mold 2 at the mating surface of the upper mold 1 and the lower mold 2.

  The molding die 1 </ b> A is provided with a plurality of valve mechanisms for starting and stopping the supply of resin (fluid resin) that has fluidity to be supplied to the cavity 3. In this embodiment, the upper mold 1 is provided with a plurality of valve mechanisms 6A and 6B that start and stop the supply of resin (fluid resin) that has fluidity to be supplied to the cavity 3. ing. Although not shown, the plurality of valve mechanisms may be provided in a distributed manner in the upper mold 1 and the lower mold 2.

  In this embodiment, each of the valve mechanisms 6A and 6B has a valve body 6a made of a cylinder, a resin flow path 6b provided inside the valve main body 6a, and starts or stops the flow of resin in the resin flow path 6a. And a valve, for example, a piston 10.

  2 and 3 are enlarged views of the valve mechanism 6A in FIG. FIG. 2 is a schematic partial cross-sectional enlarged front view showing a state in which resin flows in the resin flow path 6b of the valve mechanism 6A in the mold 1A shown in FIG. 1 (flow path communication state). FIG. 3 is a schematic partial cross-sectional enlarged front view showing a state where resin does not flow in the resin flow path 6b of the valve mechanism 6A shown in FIG. 2 (closed state of the flow path).

  The valve body 6a is provided with a piston movement hole 10a penetrating from the upper surface to the lower surface. The piston 10 is attached to the valve body 6a so as to be movable up and down while being fitted in the piston moving hole 10a. The upper part of the piston 10 is attached to a piston driving device 15. The piston drive device 15 is attached to the lower surface of the elevating upper panel 21.

  An inlet 6c of a resin flow path 6b provided inside the valve body 6a is opened on a side peripheral surface of the valve body 6a, and an outlet 6d thereof is opened on a lower surface of the valve body 6a. The resin flow path 6b includes a resin flow path 6b-1 that faces in the horizontal direction and a resin flow path 6b-2 that communicates with the resin flow path 6b-1 and faces in the vertical direction. The resin flow path 6b-2 facing in the vertical direction coincides with a part of the piston moving hole 10a. As a result, when the piston 10 descends and blocks the resin flow path 6b-1 facing in the horizontal direction, the resin mold is transferred from the resin flow path 6b-1 facing in the horizontal direction to the resin flow path 6b-2 facing in the vertical direction. Supply to tee 3 is stopped. When the supply of this resin is stopped, the resin flow path 6b-1 becomes the resin retention part 11 where the resin stays.

  A distal end portion 6 e of the valve body 6 a is inserted into a valve mechanism mounting hole 1 a provided in the upper mold 1 so as to penetrate from the upper surface of the upper mold 1 to the inner wall surface, and is embedded in the upper mold 1. A portion above the front end portion 6 e of the valve main body 6 a, that is, a rear end portion 6 f of the valve main body 6 a is located outside the upper surface of the upper mold 1. The outer diameter of the rear end portion 6f is larger than the outer diameter of the front end portion 6e, and a step is formed between the two. An O-ring 14 for sealing is provided between the lower surface of the rear end 6f and the upper surface of the mold 1. An O-ring 6g for sealing is provided around the upper opening of the piston moving hole 10a.

  The resin flow path 6b-1 (resin retaining portion 11) is located at the rear end 6f of the valve main body 6a above the front end 6e of the valve main body 6a, but the front end 6e is embedded in the upper mold 1. Therefore, it is easily affected by the temperature of the upper mold 1. That is, when the resin is a thermosetting resin, the temperature employed in the temperature control mechanisms 5a and 5b in order to cure the thermosetting resin in the cavity 3 is the temperature at which the thermosetting resin is cured. Therefore, heat corresponding to the temperature is transferred from the tip portion 6e of the valve body 6a to the resin staying portion 11, and the resin staying in the resin staying portion 11 is likely to be cured.

  On the other hand, when the resin is a thermoplastic resin, the temperature employed in the temperature control mechanisms 5a and 5b to solidify the thermoplastic resin in the cavity 3 is a temperature at which the thermoplastic resin is solidified. Heat corresponding to the temperature is transferred from the tip portion 6e of the valve body 6a to the resin staying portion 11, and the possibility that the resin staying in the resin staying portion 11 is solidified is increased.

  In order to eliminate these possibilities as much as possible, maintain the fluidity of the resin in the resin retaining portion 11 and immediately start the supply of the resin to the cavity 3 at the start of the next molding step. Each of the plurality of valve mechanisms 6A and 6B is provided with one or more temperature control systems 12a and 12b that can adjust the respective temperatures. Each temperature control system 12a, 12b is formed by, for example, a medium flow path through which a temperature adjusting medium embedded in the valve body 6a flows, or an electric heating element (for example, an electric heater) capable of temperature control.

  The temperature control systems 12a and 12b shown in FIG. 1 include medium flow paths through which a temperature adjusting medium flows. A medium that is supplied and circulated from the medium supply device provided outside the valve mechanisms 6A and 6b circulates in the medium flow path. The medium is heated or cooled depending on the purpose. For example, water or oil is used as the medium.

  In the molding die 1A, a resin supply branch pipe 1Ca of a resin Rm in a fluid state is connected to a resin inlet 6c of the valve body 6a in the valve mechanism 6A, and the valve mechanism has the same structure as the valve mechanism 6A. The resin supply branch pipe 1Cb of the resin Rm in a fluid state is connected to the inlet of the resin 6B, and these resin supply branch pipes 1Ca and 1Cb are connected to one resin supply main pipe on the upstream side thereof. Connected to 1C. The resin supply main pipe 1C is coupled to a supply source (not shown) of the resin Rm in a fluid state.

  In the mold 1A, after the reinforcing fiber base 4 is accommodated in the cavity 3, the molds 1 and 2 are closed by the mold opening / closing mechanism 1B, and the molds 1 and 2 are closed. Rm is supplied from the resin supply branch pipe 1Ca into the cavity 3 through the valve mechanism 6A. Similarly, the resin Rm is supplied from the resin supply branch pipe 1Cb into the cavity 3 via the valve mechanism 6B. After the supply of the resin Rm into the cavity 3 is completed, the supply of the resin Rm is stopped by the valve mechanisms 6A and 6B. At the same time or thereafter, the temperature in the cavity 3 is controlled by the temperature control mechanisms 5a and 5b so that the resin Rm impregnated in the reinforcing fiber base 4 in the cavity 3 is solidified, and the resin Rm After the solidification is completed, the mold opening / closing mechanism 1B opens the plurality of molds 1 and 2, and the fiber reinforced resin molded body FRP1 made of the solidified resin and the reinforcing fiber base 4 is taken out from the mold 1A.

  In the molding die 1A used in this RTM molding method, a plurality of valve mechanisms are arranged on the molding die 1A. Although depending on the size of the molding die, in the molding die 1A of FIG. 1, valve mechanisms 6A and 6B having the same configuration are arranged at equal left and right distances from the center of the upper die 1. When the surface area of the molded product to be molded is large, more valve mechanisms are arranged in the upper mold 1. Further, when the molded product to be molded is thick, a valve mechanism is also provided in the lower mold 2.

  In the molding die 1A used in this RTM molding method, one valve mechanism 6A is provided with one or more temperature control systems 12a for adjusting the temperature of the valve mechanism 6A. Furthermore, one or a plurality of temperature control systems 12b for adjusting the temperature of the valve mechanism 6B is provided in the other valve mechanism 6B.

  Each of the molds 1 and 2 of the mold 1A may be any material as long as the necessary shape of the cavity 3 can be processed, but if a metal material is used, the temperature control mechanisms 5a and 5b This is preferable because the temperatures of the molds 1 and 2 can be adjusted efficiently. As the metal, for example, aluminum, iron, or zinc alloy can be applied.

  The material of the valve body 6a of the valve mechanism is preferably a metal in consideration of heat transfer and the like. The wall surface of the piston moving hole 10a and the surface of the piston 10 are preferably subjected to a surface treatment in order to prevent wear and to prevent the resin from sticking. As the surface treatment, for example, there is a nitriding treatment.

  When the flow path is closed, the front end of the piston 10 reaches the front end of the piston moving hole 10a (the front end of the resin flow path 6b-2), that is, the inner wall surface of the upper mold 1, and the front end of the piston 10 passes through the cavity 3. If it is designed to have a shape that is continuous with the surface to be formed, it is preferable because the trace of the piston moving hole 10a (resin channel 6b-2) does not remain on the surface of the molded fiber-reinforced resin molded body.

  It is preferable that at least one temperature control system provided in the valve mechanism is disposed between the resin staying part 11 and the front end part 6e in the rear end part 6f. Thereby, it is efficiently suppressed that the influence of the temperature of the portion (tip portion 6 e) where the valve body 6 a is embedded in the mold 1 reaches the resin retention portion 11. That is, even if the embedded portion (tip portion 6e) that receives heat from the mold is at the same temperature as the mold, the temperature of the embedded portion (tip portion 6e) can be blocked by this temperature control system, and the resin retaining portion 11 is held at a temperature at which the fluidity of the resin is maintained. Therefore, since the blockage of the flow path due to the solidification (curing) of the resin in the resin flow path 6b-1 does not occur, it is possible to immediately shift to the next molding without the need for the work of removing the solidified resin. It becomes possible to form a continuous molded product having excellent properties.

  In particular, when the resin is a thermosetting resin, since the mold is heated to accelerate the curing of the supplied resin, the embedded portion of the valve mechanism that is in contact with the mold is also a mold. It becomes a high-temperature state by receiving heat from. Since the embedded portion is hot, heat transfer proceeds to other parts of the valve mechanism, and the entire valve mechanism tends to be hot. This problem is caused by cooling the valve mechanism by the temperature control system located between the resin retaining part and the part embedded in the mold of the valve mechanism, so that heat transfer from the embedded part is blocked. The staying part is preferable because it is kept at a low temperature and the curing reaction of the resin is suppressed.

  On the other hand, the portion embedded in the mold of the valve mechanism is also cooled by the cooling action by the temperature control system, and the temperature of the peripheral portion of the mold that is in contact with the embedded portion may decrease. When the temperature of the inner wall surface of the mold forming the cavity is lowered, the curing time of the resin may be prolonged, or the surface quality of the fiber reinforced resin molded product may be deteriorated due to the deterioration of the cured state.

  When it is necessary to solve this problem, another temperature control system 13 may be provided in a portion embedded in the mold of the valve mechanism. One mode in which the other temperature control system 13 is provided in the valve mechanism is shown in FIG. The valve mechanism 46A shown in FIG. 4 has the same structure as the valve mechanism 6A shown in FIG. 2 except for other parts of the temperature control system 13. 4, parts that are the same as the parts shown in FIG. 2 are given the same numbers as the part numbers shown in FIG.

  In the valve mechanism 46A shown in FIG. 4, the temperature control system 13 is of a type that heats the tip 6e of the valve mechanism 46A. By heating the portion (tip portion 6e) embedded in the molding die, temperature drop of the inner wall surface of the die 1 forming the cavity 3 is prevented. As a result, it is possible to prevent the curing time of the resin from being prolonged and the surface quality of the molded product from being deteriorated.

  Although FIG. 4 shows the case where the temperature control system 13 is embedded inside the tip end portion 6e, it may be disposed on the outer peripheral wall portion of the tip end portion 6e, or the piston 10 It may be arranged. As the temperature control system 13, a type in which a heat medium such as water, steam, oil, or the like flows through a medium flow path through which the heat medium flows can be used. Moreover, the type which arrange | positions an electric heater in the part to heat, and energizes may be sufficient. Use of an electric heater is preferable because the temperature control system 13 can be installed in a small space and the valve mechanism can be prevented from becoming large.

  FIG. 5 shows a valve mechanism shape additionally displaying a preferable dimensional relationship of the tip portion 6e in the valve mechanism 6A shown in FIG. In FIG. 5, the diameter of the portion (tip portion 6e) embedded in the molding die of the valve mechanism 6A is indicated by d (mm), and the depth embedded in the die 1 is indicated by h (mm). It is preferable that the diameter d and the depth h satisfy the relationship d ≦ h.

  The tip portion 6 e is subjected to a temperature adjusting action by the temperature control system 12 a provided between the resin staying portion 11 and the tip portion 6 e and a heat receiving action from the mold 1. When the diameter d (mm) is large, the cooling action by the temperature control system 12a is easily transmitted to the tip portion 6e, whereas the heat received from the mold 1 is not sufficiently transmitted to the center portion of the tip portion 6e. , The temperature of the central part tends to decrease. In addition, the peripheral portion of the tip portion 6e in the mold 1 is subject to a cooling action from the temperature control system 12a, and the temperature is likely to decrease. As a result, the curing time of the resin becomes long, the cured state deteriorates, and the surface quality of the molded product deteriorates.

  When the above relation d ≦ h is satisfied, the contact surface between the tip 6e and the mold 1 becomes larger with respect to the diameter d (mm), and therefore the cooling action by the temperature control system 12a is performed up to the tip 6e. In addition to being difficult to transmit, the peripheral portion of the tip 6e in the mold 1 is less cooled by the temperature control system 12a, and the temperature of the inner wall surface of the mold 1 forming the cavity 3 is less likely to be lowered. Further, the cured state of the resin becomes good, and a molded product having excellent surface quality can be obtained in a short time. It is preferable that the tip surface of the portion (tip portion) embedded in the valve mechanism mold coincides with the inner wall surface of the mold forming the cavity.

  The plurality of valve mechanisms may be provided in any of the plurality of molds forming the mold. By providing a plurality of valve mechanisms in the mold, it is possible to efficiently inject resin from the plurality of valve mechanisms into the cavity even in a cavity having a large surface area. It is possible to significantly reduce the impregnation time. The plurality of valve mechanisms may be arranged in a single mold or may be divided into a plurality of molds. In addition, the resin flow paths of the valve mechanisms may be opened and closed at the same time, or may be opened and closed at different times according to the state of the resin impregnated into the reinforcing fiber base in the cavity.

  It is preferable that the temperature control mechanism provided in the mold includes a temperature control mechanism of a different system in the peripheral portion of the portion embedded in the valve mechanism die (the tip portion of the valve mechanism) and other portions. This aspect will be described using the mold shown in FIGS. That is, in this aspect, the temperature of the peripheral portion of the tip portion 6e of the valve mechanism 6A in the mold 1 is adjusted by the temperature control mechanism 5a-1 different from the temperature control mechanism 5a, and the other portions are controlled by the temperature control mechanism 5a. The temperature will be adjusted.

  The valve mechanism is controlled to a temperature at which the resin is not cured by the temperature control system in order to prevent the resin from being cured at the resin retaining portion. On the other hand, the mold is controlled to a temperature at which the resin quickly and sufficiently cures by a temperature control mechanism. However, in the peripheral part where a part of the valve mechanism is embedded, the peripheral part is affected by the temperature of the valve mechanism, and the temperature of the peripheral part deviates from a temperature suitable for resin curing. There is. By adjusting the temperature of the general part of the mold and the peripheral part in which the valve mechanism is embedded by using a temperature control mechanism of a separate system, it is possible to achieve a temperature suitable for resin curing at each position. The general part of the mold is a part that is not affected by the temperature distribution due to the presence of the valve mechanism, and refers to a location that is approximately 50 mm or more away from the center of the valve mechanism on the inner wall surface of the mold forming the cavity.

  The system of the temperature control mechanism in the peripheral portion in which a part of the valve mechanism of the molding die is embedded is preferably disposed in the molding die so as to surround the portion in which the valve mechanism is partially embedded. Three examples of this aspect are shown in FIGS. 6, 7 and 8. FIG. Since the temperature control mechanism is disposed so as to surround the part where the valve mechanism is embedded, the temperature of the inner wall surface of the mold 1 and the temperature of the cavity 3 around the part where the valve mechanism is embedded. Can be kept substantially the same.

  In FIG. 6, two parallel temperature control mechanisms 5 a-1 are disposed on the mold 1 around the tip portion 6 e of the valve mechanism with the tip portion 6 e interposed therebetween. The temperature control mechanism 5a-1 is located with the shortest distance L to the outer peripheral surface of the tip end portion 6e. In FIG. 7, four temperature control mechanisms 5a-2 are disposed around the tip 6e in the mold 1 around the tip 6e of the valve mechanism. The temperature control mechanism 5a-2 is located with the shortest distance L to the outer peripheral surface of the tip 6e. In FIG. 8, one temperature control mechanism 5a-3 is disposed in a U shape around the tip 6e in the mold 1 in the periphery of the tip 6e of the valve mechanism. The temperature control mechanism 5a-3 is located with the shortest distance L to the outer peripheral surface of the tip 6e.

  These shortest distances L preferably satisfy the relationship of L ≦ 30 mm. When the shortest distance L exceeds 30 mm, the temperature control action by the temperature control mechanism of the mold does not sufficiently reach the tip end portion 6e of the valve mechanism, and the cured state of the resin in the cavity may deteriorate. If the shortest distance L is 30 mm or less, the temperature control action by the temperature control mechanism of the mold sufficiently works to the tip 6e of the valve mechanism, the resin in the cavity is cured quickly and well, and the surface quality is excellent. A fiber-reinforced resin molded product is obtained. If the shortest distance L is less than 5 mm, it becomes difficult to process the mold for disposing the temperature control mechanism in the mold 1, and the cost of the equipment increases, or the mold 1 and the tip of the valve mechanism are deformed due to deformation during processing. It is not preferable because a gap is generated at the interface with the portion 6e and the resin easily leaks from the cavity.

  Examples of the reinforcing fiber that forms the reinforcing fiber base used in carrying out the RTM molding method of the present invention include carbon fiber, glass fiber, aramid fiber, metal fiber, boron fiber, alumina fiber, and silicon carbide fiber. These fibers can be used alone or in combination. Among these, carbon fibers having excellent mechanical properties are preferably used. Examples of the form of the reinforcing fiber base include a sheet in which reinforcing fibers are arranged in one direction, a woven fabric made of reinforcing fibers, and a nonwoven fabric.

  In addition to the reinforcing fibers, the reinforcing fiber base material may be accompanied by a resin flow medium that promotes resin flow inside or outside. Usually, a plurality of reinforcing fiber substrates are arranged on the inner wall surface of the mold so as to follow the shape of the cavity, or a plurality of reinforcing fiber substrates are laminated in advance and applied to a certain shape. A shaped preform is created and this preform is placed on the inner wall of the mold so as to follow the shape of the cavity. Conventionally known resin fluid media are used as the resin fluid media.

  The RTM molding method according to the present invention can also be used when molding a fiber reinforced resin molded body having a laminated structure of a fiber reinforced resin and a core material. An example of such a fiber reinforced resin molded body is a sandwich structure in which fiber reinforced resin layers are disposed on both sides of a core material. Examples of the core material include an elastic body, a foam material, and a honeycomb material. For weight reduction, a foam material or a honeycomb material is preferably used. Examples of the foam material include foam materials made of a polymer material such as polyurethane, acrylic, polystyrene, polyimide, vinyl chloride, and phenol. Examples of the honeycomb material include a honeycomb structure material formed from aluminum alloy, paper, and aramid paper.

  As the resin used in carrying out the RTM molding method according to the present invention, a monomer for resin injection molding (RIM) made of a thermosetting resin or a thermoplastic resin, which has a low viscosity and can be easily impregnated into a reinforcing fiber base, is preferable. Used.

  Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenol resins, guanamine resins, polyimide resins such as bismaleide and triazine resins, furan resins, polyurethane resins, polydiallyl phthalate resins, , Melamine resin, urea resin and amino resin.

  Examples of the thermoplastic resin include polyamide resins such as nylon 6 resin, nylon 66 resin, and nylon 11 resin, or copolyamide resins of these polyamide resins, and polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, Or a copolymerized polyester resin of these polyester resins, further polycarbonate resin, polyamideimide resin, polyphenylene sulfide resin, polyphenylene oxide resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyetherimide resin, polyolefin resin, etc. Furthermore, there are thermoplastic elastomer resins represented by polyester elastomer resin, polyamide elastomer resin and the like.

  As the resin, a resin in which a plurality selected from the above-mentioned thermosetting resins, thermoplastic resins, and rubbers are blended can also be used. Among them, an epoxy resin is preferable from the viewpoint of suppressing thermal shrinkage at the time of molding, which affects the design of the automotive outer plate member.

  Generally, as an epoxy resin for composite materials, a bisphenol A type epoxy resin, a phenol novolac type epoxy resin, or a glycidylamine type epoxy resin is used as a main agent. On the other hand, as the curing agent, a curing agent obtained by combining dicyandiamide with dichlorophenyldimethylurea is preferably used because it has an excellent balance of workability and physical properties. However, it is not particularly limited, and diaminodiphenyl sulfone, aromatic diamine, acid anhydride polyamide and the like can also be used. Further, the ratio of the resin and the reinforcing fiber base is preferably in the range of 30:70 to 70:30 in terms of volume ratio, in that it retains appropriate rigidity as the outer plate, and more preferably in the volume ratio of 40. : 60 to 60:40 is preferable from the viewpoint of the impregnation property and the impregnation speed of the resin to the reinforcing fiber base material. In addition, modified epoxy resin, nylon resin, dicyclopetadiene resin blended with epoxy resin or thermoplastic resin or rubber component is preferably used from the viewpoint of reducing thermal shrinkage of FRP structure and suppressing occurrence of cracks. It is done.

  FIG. 9 shows a molding die 1A additionally displaying a temperature detection device for measuring the temperature of the die 1 and a temperature detection device for measuring the temperature of the valve mechanism in the molding die 1A shown in FIG. In the mold 1 </ b> A of FIG. 9, when the upper mold 1 and the lower mold 2 are closed, a cavity 3 is formed between the inner wall surface of the upper mold 1 and the inner wall surface of the lower mold 2. The inner wall surface of the upper mold 1 has a gently curved surface shape having a plane dimension of 800 mm × 800 mm and a height of 50 mm, and the thickness of the cavity 3 to be formed is 1.4 mm. The inner wall surface of the lower mold 2 has a shape substantially in line with the shape of the inner wall surface of the upper mold 1 so that the thickness of the cavity 3 is formed. The upper mold 1 and the lower mold 2 were each provided with a plurality of through holes, and these through holes were used as the temperature control mechanisms 5a and 5b.

  The upper mold 1 is provided with five valve mechanisms 6A so as to be substantially equally spaced. FIG. 9 shows two of the valve mechanisms 6A. The resin inlet provided on the side surface of each valve mechanism 6A was connected to a resin injector (not shown) with a nylon tube for resin supply. The lower part (tip part 6e) of the valve mechanism 6A was formed in a cylinder, and the tip part 6e was embedded in the upper mold 1 so that the tip surface reached the cavity surface. A resin discharge port was provided on the distal end surface of the distal end portion 6e. The diameter d of the embedded portion (tip portion 6e) was 30 mm, and the embedded depth h was 40 mm.

  The flow path opening / closing mechanism of the valve mechanism 6A is a piston valve type, and each is connected to a hydraulic cylinder so that it can be opened and closed. When the piston valve was opened, a resin flow path was formed so as to enter the inside of the valve mechanism laterally from the resin inlet on the side surface and extend downward from the space in which the piston valve slides to reach the resin discharge port. When the piston valve is closed, the piston descends in the resin flow path and reaches a position that is flush with the cavity. In this part, the space that becomes the resin flow path is occupied by the piston. The resin flow path between the piston sliding part is left in a space.

  Two through holes were provided in the lower part of this space, and these through holes were used as the temperature control system 12a. The cooling water supplied from the chiller provided outside was circulated through these through holes. The valve mechanism 6A is fixed to the upper mold 1 with bolts, and an O-ring is disposed between the upper mold 1 and the valve mechanism 6A. A digging was provided from the outside of the valve mechanism 6A to a position adjacent to this space, and a thermocouple 18 was arranged inside the digging so that the temperature of the part could be measured.

  In the mold, the surface temperature of the cavity (the temperature at the mold temperature measurement position 19 100 mm away from the center of the valve mechanism 6A on the cavity surface) is obtained by circulating hot water inside the through holes of the temperature control mechanisms 5a and 5b. Was set to 100 ° C. At this time, the surface temperature of the portion of the valve mechanism 6A exposed to the cavity 3 was 95 ° C., and the temperature measured by the thermocouple 18 provided in the valve mechanism 6A was 35 ° C.

The molding die is attached to the lifting device, and the lifting device upper board 21 is raised to open the molding die. After the reinforcing fiber base 4 is disposed in the cavity 3, the lifting device upper board 21 is lowered to lower the mold. Tightened. As the reinforcing fiber base material, a laminate of four CK6252C (plain weave, basis weight 315 g / m ² , reinforcing fiber T700SC-12K) manufactured by Toray Industries, Inc. was used.

  The inside of the cavity 3 was kept in a vacuum state by a vacuum pump (not shown), and the liquid resin was fed using a resin injection machine (not shown). As this liquid resin, an epoxy resin (epoxy resin TR-C35 manufactured by Toray Industries, Inc.) was used. This epoxy resin TR-C35 consists of a main agent (jER828 (manufactured by Japan Epoxy Resin Co., Ltd., epoxy resin)) and a curing agent (blend TR-C35H (imidazole derivative) manufactured by Toray Industries, Inc.). The mixing ratio was 10: 1.

  After confirming that the liquid resin is branched via the tube, enters the resin flow path from the resin inlet on the side surface of each valve mechanism 6A, and reaches the flow path opening / closing mechanism, the piston valve is raised, Was released. After confirming that the liquid resin was filled in the cavity 3, the piston valve was lowered and the flow path was closed. The time required from the start of resin injection to the filling of the liquid resin into the cavity 3 was 1 minute.

  After maintaining in this state for 17 minutes, the mold was opened, and the molded fiber-reinforced resin molded product was taken out from the mold. The manufactured fiber reinforced resin molded product was impregnated and cured with resin throughout the reinforcing fiber base, and the surface condition was also good.

  Subsequently, the molding die was cleaned, the reinforcing fiber base material having the same laminated configuration as the first time was placed in the cavity, the molding die was closed, and the second molding was performed in the same procedure as the first time. The time required for the injection of the liquid resin and the curing time were the same as the first time. The fiber-reinforced resin molded product taken out from the mold had a good surface similar to that of the first molding. The time required from taking out the first fiber reinforced resin molded product to taking out the second fiber reinforced resin molded product was as short as 22 minutes.

  In the molding die used in Example 1, for each of the five valve mechanisms, the position is 20 mm from the hole 1a in which the lower part of the valve mechanism is embedded (the position where L = 20 mm in FIG. 7). Four cartridge heaters 20 were embedded and energized and heated. As a result, when the surface temperature of the cavity 3 was maintained at 100 ° C., the surface temperature of the portion where the valve mechanism 6A was exposed to the cavity 3 was 98 ° C. The temperature measured by the thermocouple 18 provided in the valve mechanism 6A was 38 ° C.

  When the liquid resin was injected under the same conditions as in Example 1, the time required for the liquid resin to fill was 1 minute. After maintaining in this state for 15 minutes, the mold was opened, and the fiber-reinforced resin molded product was taken out from the mold. The resin was completely impregnated into the reinforcing fiber base material and cured, the surface state of the molded product was good, and a similar molded product could be obtained by shortening by 2 minutes compared to Example 1.

  Subsequently, the mold was cleaned, and molding was performed in the same procedure as in the first time, and a fiber-reinforced resin molded product having an excellent surface state similar to that in the first molding could be obtained in a short time. The time required from taking out the first fiber reinforced resin molded product to taking out the second fiber reinforced resin molded product was as short as 20 minutes.

Comparative Example 1

  Using a mold having the same cavity shape as in Example 1 but not having a valve mechanism, the surface of the cavity is made to flow through the through-hole provided in the mold in the same manner as in the mold of Example 1. The temperature was maintained at 100 ° C. A nylon tube for resin supply extending from the resin injection machine was connected to a resin inlet provided on a mating surface JF (see FIG. 9) of a plurality of molds.

  The inside of the mold was kept in a vacuum, and the liquid resin was injected into the cavity by using the same reinforcing fiber base material and liquid resin as in Example 1 to be filled. After holding in this state for 15 minutes, the mold was opened to obtain a fiber-reinforced resin molded product. The fiber-reinforced resin molded article was cured by impregnating the resin into the reinforcing fiber base material, and the surface condition was also good.

  Subsequently, the resin tube used for injection was removed from the mold and discarded, and then the mold was cleaned, and the reinforcing fiber base material was placed in the cavity with the same lamination. After the resin tube was installed on the mating surfaces JF of the plurality of molds and the mold was closed to hold the tube, the other end of the resin tube was connected to a resin injector. Thereafter, when the second molding was performed in the same procedure as the first, the time required for the injection of the liquid resin and the curing time were the same as the first. The fiber reinforced resin molded product taken out from the mold had a good surface similar to the first molding. The time required from taking out the first fiber reinforced resin to taking out the second fiber reinforced resin was 30 minutes, and it took several minutes to remove, discard, and install a new resin tube. It took a long time. Also, resin tube waste was generated.

  According to the RTM molding method of the present invention, when a liquid resin (resin in a state having fluidity) is injected into a molding die and the resin is solidified in the molding die, Inadequate solidification of the liquid resin can be prevented, and desired smooth resin injection operation and smooth start and stop operations of resin injection can be performed. Moreover, since the injection resin can be prevented from solidifying, the resin flow path can be opened and closed without using a disposable resin tube. Therefore, the workability of the entire molding cycle can be improved, and the productivity of the molded product can be improved. In addition, it is possible to reduce wastes such as resin tubes that have been generated conventionally.

  Further, if such an RTM molding method is used, the resin can be smoothly injected into the cavity of the molding die, and the tact time can be shortened when repeatedly molding, so that the FRP molded product can be reduced. Production efficiency can be greatly increased.

1: Upper mold 1A: Mold 1a: Valve mechanism mounting hole 1B: Mold opening / closing mechanism 1Bd: Lifting mechanism 1C: Resin supply main pipe 1Ca, 1Cb: Resin supply branch pipe 2: Lower mold 3: Cavity 4: Reinforced fiber base material 5a, 5b: Temperature control mechanism 5a-1, 5a-2, 5a-3: Temperature control mechanism 6A, 6B: Valve mechanism 6a: Valve body 6b: Resin channel 6b-1: Resin channel 6b- facing in the horizontal direction 2: Up and down direction resin flow path 6c: Resin flow path inlet 6d: Resin flow path outlet 6e: Valve body tip 6f: Valve body rear end 6g: O-ring 10: Piston 10a: Piston movement Hole 11: Resin staying part 12a, 12b: Temperature control system 13: Other temperature control system 14: O-ring 15: Piston drive 17: O-ring 18: Thermocouple 19: Mold temperature measurement position 20: Cartridge heater 21 : Raising board 22: Post 23: Elevating lower board 46A: Valve mechanism d: Diameter of the tip of the valve mechanism FRP1: Fiber reinforced resin molding h: Depth of embedding in the mold of the tip of the valve mechanism JF: Mold Plural types of mating surfaces L: shortest distance Rm between the tip of the valve mechanism and the temperature control mechanism Rm: resin in a fluid state

Claims (16)

(A) a plurality of molds, (b) a temperature control mechanism for adjusting the temperature of a mold provided in at least one of the plurality of molds, and (c) a mold opening / closing mechanism for opening and closing the plurality of molds, (D) When the plurality of molds are closed, a cavity formed between the inner wall surfaces of the plurality of molds, and (e) supplying resin in a fluid state to the cavities. A molding die comprising a resin introduction path and (f) a valve mechanism that is provided in the resin introduction path and starts and stops the supply of the resin from the resin introduction path to the cavity; (g) After the reinforcing fiber base is accommodated in the cavity, the plurality of molds are closed by the mold opening / closing mechanism, and (h) after the plurality of molds are closed, the resin is removed from the resin introduction path. Supplied to the cavity via the valve mechanism, (i) After the supply of fat is completed, the supply of the resin is stopped by the valve mechanism, and (j) the resin impregnated in the reinforcing fiber base in the cavity is solidified by the temperature control mechanism. The temperature in the cavity is adjusted, and (k) after the resin is solidified, the mold opening / closing mechanism opens the plurality of molds, and the fibers are made of the reinforcing fiber base and the resin. In the RTM molding method in which the reinforced resin molding is taken out of the mold,
(L) A plurality of the valve mechanisms are provided in the mold,
(M) Each of the plurality of valve mechanisms is provided with one or more temperature control systems for adjusting the temperature of the valve mechanism,
(N) The RTM molding method in which the resin having the fluidity is supplied from the plurality of valve mechanisms into the cavity.   The fluidity is maintained in the cavity by continuously flowing the temperature adjusting medium to at least one of the one or more temperature control systems provided in the valve mechanism. Even when the resin is solidified, in the state where the flow of the resin in the resin introduction path is stopped, the resin in the state having the fluidity staying in the resin introduction path The RTM molding method according to claim 1, wherein the RTM is maintained in a fluid state.   The valve mechanism is embedded in the mold at a tip portion that is a part of the valve mechanism, and the tip of the resin introduction path opens to the inner wall surface of the mold that forms the cavity via the valve mechanism. In the state where at least one of the one or more temperature control systems provided in the mold and provided in the valve mechanism is stopped in the resin introduction path, 2. The RTM molding method according to claim 1, wherein the RTM molding method is a system located between a resin retaining portion where a resin in a fluid state is retained and the tip portion of the valve mechanism.   The system located between the resin staying part and the tip of the valve mechanism is a system that allows a temperature adjusting medium to flow through a temperature adjusting medium flow path provided inside the valve mechanism. The RTM molding method according to claim 3, wherein the valve mechanism is cooled by a working medium.   The RTM molding method according to claim 3, wherein another temperature control system is disposed at the tip of the valve mechanism, and the other temperature control system heats the valve mechanism.   The RTM molding method according to claim 3, wherein a diameter d and a depth h of the tip portion of the valve mechanism satisfy a relationship of d ≦ h.   The RTM molding method according to claim 1, wherein the plurality of valve mechanisms are independently opened and closed.   4. The RTM molding method according to claim 3, wherein the temperature control mechanism provided in the mold includes a temperature control mechanism of a different system in a peripheral portion of the tip portion of the valve mechanism and other portions.   The temperature control mechanism in the periphery of the tip of the valve mechanism among the temperature control mechanisms provided in the mold is disposed in the mold so as to surround the tip of the valve mechanism. 8. The RTM molding method according to 8.   The temperature control mechanism provided in the said shaping | molding die is arrange | positioned in the position where the distance L from the interface of the said front-end | tip part of the said valve mechanism and the said mold satisfies the relationship of L <= 30mm. The described RTM molding method.   A plurality of the resin introduction paths including the plurality of valve mechanisms are coupled to the same resin supply source, and introduced into the cavity into the plurality of resin introduction paths connecting the resin supply source and the valve mechanism. The supply resin temperature adjustment mechanism which adjusts the temperature of the resin to a temperature higher than the temperature of the resin is provided, and the temperature of the resin in the resin introduction path is adjusted by the supply resin temperature adjustment mechanism. RTM molding method.   The RTM molding method according to claim 1, wherein the reinforcing fiber base is a sheet.   The RTM molding method according to claim 1, wherein the reinforcing fiber base has a core material therein.   In the cavity, a resin flow path forming medium in the cavity is disposed between an opening position on the inner wall surface of the mold of the resin introduction path and a reinforcing fiber base. The described RTM molding method.   The RTM molding method according to claim 14, wherein the media has a thickness of 0.2 to 1 mm.   The manufacturing method of the fiber reinforced resin molded object which manufactures a fiber reinforced resin molded object using the RTM molding method of Claim 1.

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